hdf5_ep

[svn-r6795] Purpose:
	Feature Add

Description:
	Added knob so that the programmer can enable or disable GPFS
	hints during runtime instead of having it only enabled at
	configure/compile time. Some of the public APIs were changed
	to add an extra parameter for this option...

Platforms tested:
	Blue (LLNL). It only affects the MPI/POSIX driver, so no need
	to test it on non-GPFS platforms.

Misc. update: